‘Just about zero.’
‘Is there any other way of noticing that an obscure star must be very near to us?’
‘It may have a large proper motion - for a star. I mean that if you watch it steadily, its own motion would change its place in the sky in a more or less straight line.’
‘Would that be noticed in this case?’
‘It might be, but not all stars have a large proper motion, even if they are close to us. They are moving in three dimensions and we see the proper motion only in a two-dimensional projection. I can explain-’
‘No, I'm continuing to take your word for it. Has this star got a large proper motion?’
‘That would take some time to determine. I do have a few older pictures of that part of the sky and I could detect an appreciable proper motion, That would need more work.’
‘But do you think it has the kind of proper motion that would force itself on astronomers, if they just happened by accident to note the star?’
‘No, I don't.’
‘Then is it possible that we on Rotor are the only ones who know about this Neighbor Star, since we're the only ones who've sent out a Far Probe? This is your field, Dr Insigna. Do you agree that we're the only ones who've sent out a Far Probe?’
‘The Far Probe isn't entirely a secret project, Mr Secretary. We've accepted experiments from the other Settlements and discussed that part of it with everyone, even Earth, which isn't too interested in astronomy these days.’
‘Yes, they leave it to the Settlements, which is sensible. But have any other Settlements sent out a Far Probe that they have kept secret?’
‘I doubt that very much, sir. They would need hyper-assistance for that, and we have kept the technique of hyper-assistance entirely secret. If they had hyper-assistance, we'd know. They'd have to perform experiments in space that would give the fact away.’
‘According to the Open Science Agreement, all data obtained by the Far Probe is to be published generally. Does that mean that you have already informed-’
Insigna interrupted indignantly. ‘Of course not. I would have to find out a good deal more before I publish. What I have now is only a preliminary result that I'm telling you in confidence.’
‘But you are not the only astronomer working on the Far Probe. I presume you've shown the results to the others.’
Insigna flushed and looked away. Then she said defensively, ‘No, I haven't. I noticed this datum. I followed it up. I worked out its significance. I. And I want to make sure I get the credit for it. There is only one star that is nearest to the Sun and I want to be in the annals of science as its discoverer.’
‘There might be a still closer one,’ and now Pitt permitted himself the first smile of the interview.
‘It would have been long known. Even my star would be known but for the very unusual existence of that tiny obscuring cloud. To have another - and closer - star is quite out of the question.’
‘Then it boils down to this, Dr Insigna. You and I are the only ones to know of the Neighbor Star. Am I right? No-one else?’
‘Yes, sir. Just you and I, so far.’
‘Not just so far. It must remain a secret to us until I am prepared to tell certain specific others.’
‘But the agreement - the Open Science Agreement-’
‘Must be ignored. There are always exceptions to everything. Your discovery involves Settlement security. If Settlement security is involved, we are not required to make the discovery an open one. We don't make hyper-assistance open, do we?’
‘But the existence of the Neighbor Star has nothing to do with Settlement security.’
‘On the contrary, Dr Insigna, it does. Perhaps you don't realize it, but you have come upon something that can change the destiny of the human species.’
She stood there, frozen, staring at him.
‘Sit down. We are conspirators, you and I, and we must be friendly. From now on, you are Eugenia to me when we're alone, and I am Janus to you.’
Insigna demurred. ‘I don't think that's proper.’
‘It will have to be, Eugenia. We can't conspire on frigid, formal terms.’
‘But I don't want to conspire with anyone about anything, and that's all there is to it. And I don't see the point about keeping secret the facts concerning the Neighbor Star.’
‘I suppose you are afraid of losing the credit.’
Insigna hesitated the merest moment, then said, ‘You can bet your last computer chip I am, Janus. I want my credit.’
‘For the moment,’ he said, ‘forget that the Neighbor Star exists. You know that I've been arguing for quite a while that Rotor ought to leave the Solar System. Where do you stand on that? Would you like to leave the Solar System?’
She shrugged. ‘I'm not sure. It would be nice to see some astronomical object close up for the first time - but it's a little frightening, too, isn't it?’
‘You mean, leaving home?’
‘Yes.’
‘But you wouldn't be leaving home. This is home. Rotor.’ His arm flipped from side to side. ‘It would come with you.’
‘Even so, Mr Sec - Janus, Rotor isn't all there is to home. We have a neighborhood, the other Settlements, the planet Earth, the whole Solar System.’
‘It's a crowded neighborhood. Eventually, some of us will have to go, whether we want to or not. On Earth there was once a time when some people had to cross mountain ranges and oceans. Two centuries ago, people on Earth had to leave their planet for Settlements. This is just another step forward in a very old story.’
‘I understand, but there are some people who never went. There are people who are still on Earth. There are people who've lived in one small region of Earth for countless generations.’
‘And you want to be one of these nonmovers.’
‘I think my husband Crile does. He's quite outspoken about your views, Janus.’
‘Well, we have freedom of speech and thought on Rotor, so he can disagree with me if he pleases. Now here's something else I'd like to ask you. When people generally, on Rotor or elsewhere, think of moving away from the Solar System, where do they think of going?’
‘Alpha Centauri, of course. It's the star everyone believes is closest. Even with hyper-assistance, we can't end up going faster than the speed of light on the average, so it would take us four years. Anywhere else, it would take much longer, and four years is long enough to travel.’
‘Suppose it were possible to travel even faster, and suppose you could reach much farther than Alpha Centauri, where would you go then?’
Insigna paused in thought awhile, then said, ‘I suppose - still Alpha Centauri. It would still be in the old neighborhood. The stars at night would still seem quite the same. That would give us a comfortable feeling. We would be closer to home, if we wanted to return. Besides, Alpha Centauri A, which is the largest of the three-star Alpha Centauri system, is practically a twin of the Sun. Alpha Centauri B is smaller, but not too small. Even if you ignore Alpha Centauri C, a red dwarf, you would still have two stars for the price of one, so to speak, two sets of planets.’
‘Suppose a Settlement has left for Alpha Centauri and found decent habitability there and settled down to build a new world, and back in the Solar System, it was known that this had happened. Where would the next Settlements go, once they decided to leave the Solar System?’
‘To Alpha Centauri, of course,’ said Insigna without hesitation.
‘So the human species would tend to go to the obvious place, and if one Settlement succeeds, others would follow quickly, until the new world was as crowded as the old, until there were many people with many cultures, and eventually many Settlements with many ecologies.’
‘Then it will be time to move on to other stars.’
‘But always, Eugenia, success in one place will draw other Settlements. A salubrious star, a good planet, will bring others flocking.’
‘I suppose so.’
‘But if we go to a star that is only a little over two light-years away, only half the distance of Alpha Centauri, and no-one knows about it except us, who will follow us?’